add stream example

Author: sxwebdev

Makefile

@@ -1,6 +1,6 @@
 current_dir = $(shell pwd)
 
-PATH  := $(PATH):$(PWD)/bin:$(current_dir)/frontend/node_modules/@protobuf-ts/plugin/bin
+PATH := $(PATH):$(PWD)/bin:$(current_dir)/frontend/node_modules/@protobuf-ts/plugin/bin
 
 genproto:
 	rm -rf $(current_dir)/backend/pb/*
@@ -10,10 +10,11 @@ genproto:
 	--go-grpc_out=:$(current_dir)/backend/pb \
 	--ts_out $(current_dir)/frontend/src/api/proto \
 	--ts_opt generate_dependencies \
-	hello.proto
+	example.proto
 	npx prettier --write --log-level=error $(current_dir)/frontend/src/api/proto/*
 
 start:
+	docker compose build --no-cache
 	docker compose up -d
 	open http://localhost:3000
 

README.md

@@ -2,6 +2,8 @@
 
 This repository contains an example of using grpc-web with a backend written in golang.
 
+![Preview](https://github.com/sxwebdev/grpc-web-example/blob/master/preview.png?raw=true)
+
 ## Tech stack
 
 - Backend: `Golang`

backend/.air.toml

@@ -0,0 +1,32 @@
+# Working directory
+root = "."
+tmp_dir = ".tmp"
+
+[build]
+# Just plain old shell command. You could use `make` as well.
+cmd = "make build"
+# Binary file yields from `cmd`.
+bin = ".build/app"
+# This log file places in your tmp_dir.
+log = "air_errors.log"
+# Watch these filename extensions.
+include_ext = ["go"]
+# Ignore these filename extensions or directories.
+exclude_dir = [".tmp", "/sql"]
+# It's not necessary to trigger build each time file changes if it's too frequent.
+delay = 1000 # ms
+
+[log]
+# Show log time
+time = true
+
+[color]
+# Customize each part's color. If no color found, use the raw app log.
+main = "magenta"
+watcher = "cyan"
+build = "yellow"
+runner = "green"
+
+[misc]
+# Delete tmp directory on exit
+clean_on_exit = true

backend/Makefile

@@ -0,0 +1,13 @@
+current_dir = $(shell pwd)
+
+PATH := $(PATH):$(PWD)/bin:$(current_dir)/frontend/node_modules/@protobuf-ts/plugin/bin
+
+start:
+	go run -v main.go
+
+build:
+	go build -o ./.build/app -v main.go
+
+watch:
+	air -c .air.toml
+

backend/internal/api/grpc-web.go

@@ -0,0 +1,74 @@
+package api
+
+import (
+	"context"
+	"fmt"
+	"grpc-web-example/pb"
+	"time"
+
+	"github.com/tkcrm/mx/logger"
+	"google.golang.org/grpc"
+	"google.golang.org/protobuf/types/known/timestamppb"
+)
+
+type grpcWebServer struct {
+	logger logger.Logger
+	ctx    context.Context
+
+	pb.UnimplementedServiceServer
+}
+
+func NewGrpcWebServer(ctx context.Context, logger logger.Logger) *grpcWebServer {
+	return &grpcWebServer{
+		logger: logger,
+		ctx:    ctx,
+	}
+}
+
+func (s *grpcWebServer) Name() string { return "grpc-web-server" }
+
+func (s *grpcWebServer) Register(srv *grpc.Server) {
+	pb.RegisterServiceServer(srv, s)
+}
+
+func (s *grpcWebServer) Rpc(ctx context.Context, req *pb.RpcRequest) (*pb.RpcResponse, error) {
+	if req.Text == "" {
+		return nil, fmt.Errorf("empty text")
+	}
+
+	return &pb.RpcResponse{
+		Response: fmt.Sprintf("You requested: %s", req.Text),
+		Date:     timestamppb.Now(),
+	}, nil
+}
+
+func (s *grpcWebServer) Stream(req *pb.StreamRequest, stream pb.Service_StreamServer) error {
+	errChan := make(chan error, 1)
+	go func() {
+		var lastValue int32 = 0
+
+		for {
+			lastValue++
+
+			replyMsg := &pb.StreamResponse{
+				RandInteger: lastValue,
+				Date:        timestamppb.New(time.Now()),
+			}
+
+			if err := stream.Send(replyMsg); err != nil {
+				errChan <- err
+				return
+			}
+
+			time.Sleep(time.Second)
+		}
+	}()
+
+	select {
+	case <-s.ctx.Done():
+	case err := <-errChan:
+		return err
+	}
+
+	return nil
+}

backend/internal/api/hello.go

@@ -21,12 +21,12 @@ func main() {
 	)
 
 	// grpc servers
-	helloServer := api.NewHelloServer()
+	grpcWebServer := api.NewGrpcWebServer(ln.Context(), logger)
 
 	// grpc instance
 	grpcServer := grpc_transport.NewServer(
 		grpc_transport.WithLogger(logger),
-		grpc_transport.WithServices(helloServer),
+		grpc_transport.WithServices(grpcWebServer),
 	)
 
 	ln.ServicesRunner().Register(